You are lucky that Mary is willing to share. And divorce is so hard on everyone, but Granmas get hurt too. When my middle son divorced, the ex hated me( the whole time they were married) and she moved with the kids 6 hours away. My son was allowed to have them for school breaks and summer visit. It was really hard for the first 18months, then she moved back here. And although things were rough, she needed my help , so I got to have them a lot.Now( many years later) she loves me and considers me her good friend, and the kids live with my son and I see them more often than she does. It's a really long story, but things do work out. Now we just pray it works out for the youngest son with his kids. At least that ex didn't and doesn'T hate me!!